The Maryland Campaign, or the Antietam Campaign
(September 4-20, 1862) is widely considered one of the major
turning points of the American Civil War.
Confederate Gen. Robert
E. Lee's first invasion of the North was repulsed by Maj. Gen.
George B. McClellan and the Army of the Potomac, who moved to
intercept Lee and his Army of Northern Virginia and eventually
attacked it near Sharpsburg, Maryland.
The resulting Battle of
Antietam was the bloodiest single-day battle in American history.